A258081 Values of k in A071580.

1, 1, 1, 1, 2, 10, 12, 10, 21, 25, 70, 670, 239, 2115, 586, 1619, 26800, 2505, 99019, 40903, 285641, 67166, 1852765

Offset: 1

Author

Andrew R. Booker, May 19 2015

Keywords

• nonn
• hard
• more

Comments

The first 23 terms were found using gwnum, and the first 22 have been independently checked using gmp.

Links

• Mersenne Forum, A071580

Crossrefs

Cf. A061092, A072532, A113334.

Programs

PARI

terms=12; p=2; for(n=2, terms, q=p+1; while(!ispseudoprime(q), q=q+p); print1(q\p,", "); p=p*q) \\ Serge Batalov, May 19 2015